Rock bit



Oct. 31, 1939. v A. c. CATLAND, 2,177,866

ROCK BIT Filed June 22, 1958 2 Sheets-Sheet l iii 9Y1.

O ;t. 31, 1939. A. c. CATLAND ROCK BIT Filed June 22, 1938 2 Sheets-Sheet 2 as WW Patented Oct. 31, 1939' UNITED STATES I PATENT OFFICE 2,177,866 Rocx'm'r Alfred C. Catland, Alhambra, Oalllk, assignor to Globe Gil Tools Company, Los'Nietos, Call, a. corporation of California Application June 22, 193s, Serial him-215,145

6 Claims.

This invention relates to well drilling tools and relates more particularlfto bits for use in the rotary method of well drilling. A general object of this invention is to provide a sturdy longwearing and effective rock 'bit or roller bit.

Another object of this invention is to provide a rock bit of increased strength and improved operation. 1

Another object of thisinvention is to provide 710 a rock bit that is economical to construct by reason of the simplified and reduced machine work involved in its manufacture.

' Another object of this invention is to provide an improved 'rock bit in which the pins or supports carrying the outer roller cutters areintegral with the bit body thereby eliminating joints at highly stressed points and increasing the rigidity of the bit. I

Another object of this invention is to provide van a rock bit. in which the central bridge or web o and forces between the cutter supporting pins and the web.

A further object of this invention is to provide an improved rock bit embodying bearings for the roller cutters involving a minimum number 35 of parts securely locked against vibration.

The various objects and features of my invention will be-fully understood from the following detailed description of a typical preferred .form and application of the invention, through- V out which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of the improved bit of this invention with the lower portion. broken away to show the central web and the outer 45 cutter assemblies in vertical cross section. .Fig.

2 is an enlarged fragmentary detailed sectional view taken as indicated by line 2--2 on Fig. 1; Fig. 3 is a fragmentary vvertical detailed sectional view taken as indicated by line 3--3 on Fig. 5. Fig. 4 is a fragmentary vertical detailed sectional view of the improved bit illustrating the inner and center cutters and their mounting means, and Fig. 5 is an enlarged fragmentary vertlcal detailed sectional view illustrating a pair of inner and center cutters and their mounting means showing a part of the bearing member in side elevation.

The improved rock bit of the present invention may be said to comprise, generally,.a body III, a central bridge or web ll secured to the body Ill, outer roller cutters l2, means 13 rotatably supporting the outer cutters l2, sets or pairs of inner and center cutters I4 and I5 and means l6 rotatably supporting the sets of cutters I4 and l5.

10 The body I is adapted to be connected with the lower end of a rotary well. drilling string. The upper end of the body I0 is provided with means for connection with the drilling string and the lower portion of the body is formed to .15

receive the cutters l2, l4 and ii. In the typical case illustrated a tapered screw threaded pin IT is provided on the upper end of the body ill to facilitate the connection of the bit with the drilling string. A pair of diametrically opposite legs I8 is provided on the lower end of the body Ill. The legs I8 project downwardly and outwardly from the body Ill. The inner sides IQ of the legs l8 are generally flat and slope downwardly and outwardly with respect to .the central vertical axis of the bit. A second pair oflegs 20 is provided on the lower end of the body In. The legs 20 are equally spaced between the legs l8 and are diametrically opposite. In-the construction illustrated the legs 20 project downwardly and'outwardly from the body I!) and the lower parts of the legs2ll are substantially vertical. The vertical lower parts of the legs 20 have fiat substantially vertical inner surfaces or inner sides 22. The legs l8 and 20 are prefer ably integral with the body III. A central fluid socket or passage 23 enters the body I!) from the upper end of-its pin l1 and a piurality" of ports 24 is provided in the body to discharge the circulation fluid from the lower end of the passage 23. The ports 24 may be lined with beans or nozzles 25 which direct the fluid downwardly against the cutters l2 and the cutters l4 and IS. The bridge or web II is a spider-like element along the opposite edges of the central part 26.

The web ll is provided with a flat upper end which opposes a downwardly facing surface 28 -on the lower end of the body Ill. In accordance secured or joined to the body III to assist in carrying the cutter mounting means l3 and [6. The

with the invention the upper end of the web ll spaced relation is secured to the body surface 28 by welding 29. The sides of the central web part 26 oppose the inner sides 22 of the legs 20. Bosses 30 are provided on the opposite sides of the web part 23 and project toward the opposing legs 20. The side parts 21 of the web II have downwardly and outwardly sloping faces 3| spaced from and opposing the inner sides I 9 of the legs l8. The lower parts of the surfaces 3| slope outwardly at an increased angle. The web I! is proportioned so that its lower end is in approximately the same plane as the lower ends of the body legs l8 and 20.

The web being a separately formed member is easily and inexpensively machined, that is, its bosses 30 and its surfaces 3| are fully exposed and accessible prior to the attachment of the web to the body l0. Further, the inner sides I9 and 22 of the body legs l8 and 20, respectively,-

and the other internal body surfaces are all easily accessible for machining before the attachment of the web H to the body.

The outer cutters |2 are tubular frusto-conical members rotatably supported between the legs l3 and the opposing web parts 21. The cutters |2 are provided to act on the outer portion of the well bore to cut the bore to gauge. Spaced peripheral cutting teeth 32 are provided on the outer cutters '|2. The central longitudinal openings 33 of the tubular cutters l2 are of substantial ;diameter and the opposite ends of the cutters are flat and normal to the axis of their openings 33. The cutters |2 are arranged so that their large ends face outwardly and their small ends face inwardly with respect to the vertical axis of the bit.

The means l3 for rotatably supporting the outer cutters l2 mount them between the legs l9 and the web parts 21 for rotation about downwardly and inwardly inclined axes. The means '|3 include downwardly and inwardly projecting pins 34 on the legs I 8. It is a feature of the invention that the pins 34 are integral with the body legs I8. The pins 34 being integral with the legs l8 eliminate joints between the" cutter supporting means and the body legs l3 and directly transmit the forcesand'pressures from thebearing parts to the body legs. The pins 34 proiect downwardly and inwardly toward the central vertical axis of the bit and terminate in to the surfaces 3| of the web parts 21. I i

The cutter mounting means v|3 further include tubular bearing members 35 arranged .on the pins 34 and received in the openings 33 of the outer cutters l2. The outer ends of the members 35 bear on the inner sidesl9 of the legsl8 and have radial annular flanges 36. Welds 31 may fix the flanges.36 to the lower end portions of the legs l3 to prevent vibration of the bearing members 35 during the operation of the bit. The flanges 36 partially overlie or overlap the outer ends of the cutters |2 to close the outer ends of their openings 33. The flanges 36 serveto prevent the entrance of'mud and'cuttings' into the outer ends of the cutter openings 33 andin the preferred construction the flanges 36 are partially inset or recessed in the outer ends of the cutters. The bearing members 35 are of sufilcient length to project inwardly beyond the inner ends. of the pins 34. I

The cutter supporting means |3 are in the nature of anti-friction bearingmeans. Spaced annular ball races or grooves 31 are provided on each bearing member 35 andthe walls of the cutter openings 33 have snnnar grooves 36 opposing the grooves 31. Series of. balls 39 are arranged in the sets of opposing grooves 31 and 39 to rotatably support the cutters l2 with a minimum of friction. The grooves 31 and 38 are of substantial depth so that the balls 39 are operable to transmit and thrusts in both directions, as well as radial thrusts, so that the balls may form the sole means for rotatablysupporting the cutters |2 on the bearing members 35. Radial openings 40 are provided in the bearing members 35 and extend from their openings or interiors to their grooves 31. The openings 4|] admit the balls 39 to the pairs of opposing grooves 31 and 38 during the assembling of the cutters on the bearing members. Plugs 4| occupy the openings 40 to prevent the escape of the balls 39 from the opposing grooves 31 and 38. The outer ends of the plugs 4| are shaped to be flush with and to conform to the walls of their respective grooves 31. The inner ends of the plugs 4| bear on the pins 34 to hold the plugs against inward movement. Means areprovided for holding or keying the plugs 4| in place. Internal longitudinal grooves or key-ways 42 are provided in the bearing members 35 and keys 43 are provided on the inner ends of the plugs. to cooperate with the key-ways 42 to prevent turning and outward movement of the plugs.

The means l3 further include washers or nuts 44 on the web parts 21. The nuts 44 are rigid with the web parts 21 and may be formed integral with the web II or may be welded to the web surfaces 3| as at 45. The nuts 44 are washerlike elements of substantial diameter and cover 'or extend over substantially the entire inner ends of the cutters l2. The nuts may be partially inset or recessed in the inner ends of the cutters l2. Itwill be apparent how the nuts 44 prevent the entrance of mud and cuttings to the inner ends of the cutter openings 33. The inner ends of the bearing members 35 preferably bear against the nuts 44. The nuts 44 may be thickened to have their central parts extend into the inner ends of the bearing members 35. Cap screws 46 are passed inwardly through longitudinal openings 41 in the legs l3 and their pins 34.

41. The screws 46 assist in attaching the web II to the body "I and assume or assist in assuming certain of .the forces on the cutter assemblies. The outer cutters l2 supported as just described are rotatable about downwardly and inwardly inclined axes and project downwardly and outwardly beyond the lower ends of the legs II to cut the wellbore to gauge.

The inner cutters l4 and the center cutters l5 are provided act on the formation at the inner portion of the well bore. The inner and center cutters '|4-and l5 are provided in sets or pairs positioned at opposite sides of the central vertical 4 axis of the bit, each pair including an inner cutter l4 and a center cutter i5. The inner cutters M are frusto-conical roller cutters having pitched peripheries and flat ends. The central longitudinal openings 43 of the inner cutters H are of substantial diameter and have reduced inner end parts. Suitable cutting teeth 49 'are provided on the peripheries of the cutters H. The inner cutters |4 are arranged with their large ends facing outwardly.

The center cutters l5 are located at the inner ends of the inner cutters l4 and are in co-axial relation with the inner cutters. The center cutters l5 are smaller in diameter than the inner cutters l4 and are preferably cylindrical. Spaced peripheral cutting teeth 56 are provided on the center cutters l5. The longitudinal openings 5| in the center cutters l5 are-of the same diameter as the reduced inner portions of the openings 46 r in the inner cutters 4. The openings 5| in the center cutters l5 receive the bosses 36 with slight clearance. Annular flanges or shoulders 52 are provided at the bases of the bosses 36 and are received in counter-bores of the openings 5|. The shoulders 52 assist in preventing the entrance of mud and cuttings to the openings 5|.

The means vl6 for rotatably mounting the pairs of inner and center cutters I4 and I5 includes a "single tubular bushing or bearing member 53 for flanges 54 overlap substantial portions of the outer ends of the cutters l4 and are preferably partially inset or recessed in the ends of the cutters. The flanges 54'aid in preventing'the en-" trance of mud and cuttings to the cutter openings 48. Lugs 55 are provided on the flanges 54 and welds 56 secure the lugs 55 to the lower ends of the legs 26. The lugs 55 are formed to engage upwardly against the lower ends of the legs 20. and this engagement, together with the welds 56, prevents rotation of the bearing members 53. The bearing members 53 being welded to the bodylegs 20 are effectively held against vibration.

The means I6 is in the nature of an anti-friction bearing means operating to support the cutters l4 and-l5 with a minimum of friction. A plurality of spaced annular ball grooves 56 is provided in the wall of the opening 48 in each cutter I4. Circumferentially spaced ball grooves 51 are provided in the bearing members 53 to oppose the grooves 56.v In the form of the invention illustrated there are three sets or pairs of opposing grooves 56 and 51 for each cutter l4. Balls 56 are arranged in the opposing grooves 56 and 51 to rotatably support the cutters l4 on the bearing members 53. The grooves 56 and 51 are of such depth-that the balls 58 transmit end thrusts in both directions as well as radial thrusts.

A pair of spaced .annular ball grooves 59 is provided in the wall of the opening 5| of eachlcutter l5. A groove 66 is provided in each bearing member 53 to oppose the innermost groove 59 inthe surrounding cutter IS. The grooves 66 are at the inner ends of the members 53 and have their inner sides open, as illustrated in Figs. 4 and 5 of the drawings. Annular ball grooves 6| are provided in the bearing members 53 to oppose the other grooves 59 in the cutters l5. Series of balls 62 are arranged in the opposing races or grooves 59 and 60 and 59 and 6| to rotatably support the cutters 5 on the bearing members 53. The opposing grooves 59 and 6| are of such depth that the balls 62 received in them are adapted 120- transmit end thrusts in'both directions as well as the radial thrusts. The balls 62 in the grooves .gaged in the opposing grooves 59 and 66. The

'member 53 to communicate with its groove 6|. Q0

on the inner ends of the plugs 64 and cooperate vided in the web part, 26 in axial alignment with One end portion of the shaft 10 is threaded in one ends of the plugs 64 and to prevent inward 59 and 66 are capable of transmitting outward end thrusts as well-as radial thrusts. The corners of the bosses '30 may be ground oif or cut away to have suitable clearance with the balls 62 engrooves 60 being open at the inner ends of the bearing members 53 allow the easy arrangement of the balls 62 in the opposing grooves 59 and 66 when the parts are assembled.

Radial bores-or openings 63 are provided in the bearing members 53 and extend inwardly from their'ball grooves 51. The openings 63 pass or admit the balls 58 to the registering grooves 56 and 51 when the cutters M are assembled on the bearing members 53. Plugs 64 occupy the openings 63 to prevent the escape of the balls 56 andpthe outer ends of the plugs 64 are shaped to conform with the walls of the grooves 51. A radial opening 15 is provided in each bearing The openings 15 pass or admit the balls 62 to the opposing grooves 59 and 6| when the cutters l5 are assembled on the bearing members 53. Plugs 65 occupy the openings 15 and the outer ends of the plugs 65 are shaped to conform with the walls of the grooves 6|. 7

Means are provided for preventing turning and outward movement of the plugs 64 and 65. An internal -longitudinal key-way 66 is provided at each bearing member 53. Keys 61 are provided with the key-ways 66. Similar keys 68 are formed on the inner ends of the plugs 65 and cooperate with the key-ways 66. The keys 61 and 68 engaged in the key-ways 66 prevent turning and outward movement of their respective plugs 64 and 65. The inner cutters I4.and the center cutters l5 are supported by bearing means in such a manner that thrust washers are unnecessary and the adjacent cutters are at all times free of one another.

The cutter mounting means l6 further includes a single supporting pin or shaft 16 for carrying the two bearing members 53. Horizontal or transverse openings 1| are provided in the two body legs 26 and a transverse opening 12 is prothe openings 1|. The shaft 10 is arranged through or carried in the aligned openings 1| and 12. The shaft 10 extends through the tubular bearing members 53 to support the same.

opening 1| and a head 13 is formed on the other end of the shaft and is received in the other opening 1|. It will be apparent how the single pin or. shaft 10 serves to support two cutter units or assemblies comprising the bearing members 53 and the cutters l4 and 5. The opening 12 in the web part 26 is co-axial with the bosses 36 and extends through the bosses to be of substantial length and to provide a maximum support for the intermediate portion of the shaft 16. The pin or shaft "cooperates with the inner movement of the plugs. In the preferred'cono5 struction the bearing members 53 are formed and mounted so that the openings 63 and 15 are in their upper sides or portions. With this relationship of parts the walls of the grooves 51 and 6| at the openings 63 and 15 and the end parts of the 70 plugs 64 and 65 are relieved of the heavier drilling forces. 1

The means |6 just described supports the inr ner cutters l4 for rotation abouts. horizontal axis and to project downwardly beyond the lower ends of the body legs 20 so that they act on the formation at the bottom of the well bore. The center cutters I5 are supported by the means l6 to rotate about a transverse or horizontal axis and to project downwardly beyond the lower end of the web H to cut the central or inner part of the well bore. a

It is believed that the operation of the bit provided by this invention will be readily understood from the foregoing detailed description. In operation the bit body In is secured to the lower end of a well drilling string and the string is rotated and fed downwardly in the usual manner. Circulation fluid is pumped down through the drilling string to discharge from the nozzles 25.

This fluid flushes the cutters 12, I4 and I5 and maintains the necessary turbulence in the bottom of the well. The outer roller cutters 12 projecting downwardly beyond the body legs I8 cut the well bore to gauge and make anannular cut in the bottom of the well. inner cutters l4 and'center cutters l5 act on the bottom wall of the well bore to drill the inner portion of the well.

.The several cutters of the bit are supported by dependable anti-friction bearing means to rotate independently and with a minimum of friction.

and application of my invention, I do not wish to be limited or restricted to. the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A rotary well bit comprising a body having spaced integral downwardly projecting legs, inwardly projecting pins integral with the legs, a web at the lower end of the body having parts at the inner ends of the pin, welding securing the web to the body, roller cutters rotatably supported on the pins and having sockets in their inner ends receiving said parts whereby the inner ends of the cutters are closed by said parts, said pins having openings, and screws passed through the openings and threaded in said parts.

2. In a rock bit a body having'a depending leg, an integral pin on the inner side of the leg, 9. depending web on the body, a rotatable roller The sets or pairs of cutter on the pin, a nut welded on the web and extending across the inner end of the cutter, the leg and pin having an opening, and a screw extending through said opening and threaded in the nut.

3. In a rock bit a body having 9. depending leg, an integral pin on the inner side of the leg, a depending web on the body, a bearing member on the pin, a roller cutter, balls rotatably supporting the cutter on the bearing member, the pin having an opening, a nut on the web engaging the inner end of the bearing member and closing the inner end of the cutter, and a screw passed through the opening and threaded in the nut to connect the leg and web.

4. A well bit comprising a body having a pair of diametrically opposite legs, a web at the lower end of the body, welding'securing the web to the .body, nuts welded on. the web and opposing the legs, pins integral with and projecting from the legs toward said nuts, bearing members on the pins between the legs and said nuts, outer roller cutters rotatably supported on the last mentioned bearing members, said nuts engaging over the inner ends of the outer cutters to close the same, said pins having openings, and screws passed through the openings and threaded in said nuts.

5. In a rock bit, a body having a depending leg, a web at the lower end of the body, welding securing the web to the body, an integral pin on the leg projecting toward the web, a tubular roller surrounding the pin and having a recess in its inner end, a part joined with the web received in said recess of the cutter and overlying the inner end of the cutter, a tubular bearing member on the pin extending through the cutter from said part to the leg and partially receiving said part, a flange on the bearing member overlying the other end of the cutter to close the same, and anti-friction bearing elements rotatably supporting the cutter on the bearing member.

6. In a rock bit, a body having a depending leg, a web at the lower end of the body, welding securing the web to the body, an integral pin on the leg projecting toward the web, there being an opening extending through the leg and pin, a tubular roller cutter surrounding the pin, a part on the web entering the inner end of the cutter and overlying the inner end of the cutter to close the same, a bearing meniber on the pin between said partand the leg, the central portion of said part being thickened to extend into the bearing member, a flange on the bearing member overlying the outer end of the cutter'to close the same, anti-friction elements supporting the cutter on the bearing member for rotation, and a screw passed through said opening and threaded in the thickened central portion of said part.

. ALFRED Q. CATLAND. 

